I am still using operamail. For me it is the simplest, fastest and easiest way to check my mails. I have 3 mails synchronized. Currently i use two instances of Opera: - opera 12.17 mainly for the mail client and opera 28 for browsing. I wish i'd had the mail client integrated in the latest version of opera but in my searches i see that it is an abandonware. Very sad thing, i guess everything is evolving, and finally i will move tho something else. I used opera for a very long time and i think i use it now from stubbornness. Don't get me wrong, i like the new opera, but it lacks some very important things for me - like digital signature implementation, mail client. I tried Chrome (which is faster, more stable, can easy replace any browser), but i did not feel like home. I guess i will use 3 or more browsers at a time -one for browsing (opera), one for work with digital certificates and occasional browsing for pages opera 28 crashes(chrome) and one for mail (opera 12.17). Pfew, kind of complicated, no? But you know the saying: The shortest way is the way that you know best!
Enjoy your freedom of choice!